This eco-friendly dehumidifier silently and reliably protects against mold, mildew and moisture in areas larger than the Eva-Dry E-333, units and lasts 30-60 days before renewing. Special features of the E-500 includes: the unit works in areas up to 500 cubic feet, requires no batteries or cords for use, is 100% renewable, works up to ten years, is compact/silent, always spill and mess free and is non-toxic, child and pet safe! The unit measures 8" L , 2 ½" W, 5 ½" H. Prevent rust to guns and expensive ammunition and other damage caused by excess moisture.